DataFlash: use AHRS_View for RATE log msg

libraries/DataFlash/DataFlash.h

@@ -138,7 +138,7 @@ public:
                                const AP_Mission::Mission_Command &cmd);
     void Log_Write_Origin(uint8_t origin_type, const Location &loc);
     void Log_Write_RPM(const AP_RPM &rpm_sensor);
-    void Log_Write_Rate(const AP_AHRS &ahrs,
+    void Log_Write_Rate(const AP_AHRS_View *ahrs,
                         const AP_Motors &motors,
                         const AC_AttitudeControl &attitude_control,
                         const AC_PosControl &pos_control);

libraries/DataFlash/LogFile.cpp

@@ -1621,7 +1621,7 @@ void DataFlash_Class::Log_Write_RPM(const AP_RPM &rpm_sensor)
 }
 
 // Write a rate packet
-void DataFlash_Class::Log_Write_Rate(const AP_AHRS &ahrs,
+void DataFlash_Class::Log_Write_Rate(const AP_AHRS_View *ahrs,
                                      const AP_Motors &motors,
                                      const AC_AttitudeControl &attitude_control,
                                      const AC_PosControl &pos_control)
@@ -1632,16 +1632,16 @@ void DataFlash_Class::Log_Write_Rate(const AP_AHRS &ahrs,
         LOG_PACKET_HEADER_INIT(LOG_RATE_MSG),
         time_us         : AP_HAL::micros64(),
         control_roll    : degrees(rate_targets.x),
-        roll            : degrees(ahrs.get_gyro().x),
+        roll            : degrees(ahrs->get_gyro().x),
         roll_out        : motors.get_roll(),
         control_pitch   : degrees(rate_targets.y),
-        pitch           : degrees(ahrs.get_gyro().y),
+        pitch           : degrees(ahrs->get_gyro().y),
         pitch_out       : motors.get_pitch(),
         control_yaw     : degrees(rate_targets.z),
-        yaw             : degrees(ahrs.get_gyro().z),
+        yaw             : degrees(ahrs->get_gyro().z),
         yaw_out         : motors.get_yaw(),
         control_accel   : (float)accel_target.z,
-        accel           : (float)(-(ahrs.get_accel_ef_blended().z + GRAVITY_MSS) * 100.0f),
+        accel           : (float)(-(ahrs->get_accel_ef_blended().z + GRAVITY_MSS) * 100.0f),
         accel_out       : motors.get_throttle()
     };
     WriteBlock(&pkt_rate, sizeof(pkt_rate));